211540447 has 2 divisors, whose sum is σ = 211540448. Its totient is φ = 211540446.

The previous prime is 211540423. The next prime is 211540457. The reversal of 211540447 is 744045112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 211540447 - 2¹⁹ = 211016159 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211540457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105770223 + 105770224.

It is an arithmetic number, because the mean of its divisors is an integer number (105770224).

Almost surely, 2^211540447 is an apocalyptic number.

211540447 is a deficient number, since it is larger than the sum of its proper divisors (1).

211540447 is an equidigital number, since it uses as much as digits as its factorization.

211540447 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4480, while the sum is 28.

The square root of 211540447 is about 14544.4301022763. The cubic root of 211540447 is about 595.8420363843.

Adding to 211540447 its reverse (744045112), we get a palindrome (955585559).

The spelling of 211540447 in words is "two hundred eleven million, five hundred forty thousand, four hundred forty-seven".